Renovating old fruit trees
Written by Gloucestershire Orchard Group
Neglected trees, often planted much too closely to begin with, are sometimes so dense that many branches are dead through canker or silver leaf. Fungal infection may be rampant. Trees may interlock, having grown into each other's allotted space. Moss and lichen may festoon the branches, making a very pretty picture when the sun is low on a winter evening, but in a wet spring providing the ideal dampness of atmosphere to encourage scab and canker infection.
In such trees as these practically all the branches and twigs which lie submerged beneath the outer shape of the tree are bare of live buds, since only those portions of the branches which can reach daylight can function normally as regards leaf and fruit production. No leaf means no fruit buds.
Such trees might also benefit from drainage and manuring, but here we will concern ourselves just with pruning.
But before you start to prune, remember that a lot of orchard wildlife depends on dead and decaying wood and rot holes. It is usually possible to achieve a compromise, but you will need to conserve some unproductive wood where nature conservation is high priority
Pruning Old Trees
First cut out all the dead wood and stack it up so that you can walk around beneath the tree. You can then decide whether (a) to head back a number of main branches so that fresh growths will be thrown up, with a possibility of later removal or heading back of the branches which have been left uncut; or (b) cut out completely enough branches to allow ample space for those remaining. The first option of heading back is best for old trees, the second option of cutting out completely is for trees which are not unduly old but are overcrowded.
To decide on what to remove, make up your mind not to allow main branches to underlie each other unless they are at least 3 ft apart. Remove crossing branches. Try to visualise your tree's top as having a number of well-separated branches radiating out from a common centre and more or less equally spaced.
The aim of thinning is to let enough daylight in to energise fresh growth and better bud. After an orchard has been drastically thinned it is common to see the leaf looking yellow and sickly. Though some of this may be due to root damage if old stumps have been removed, it may equally be due to the weakness of bud exposed to more light than ever went to form it in the previous year. Two years should see all these troubles over and done with.
It is wrong to be too drastic in one year's pruning either among a collection of orchard trees or when thinning out a single specimen. To do so may induce a dense forest of new young growth which, being unduly soft and sappy, falls easy prey to scab and canker, and is not wanted in any case. The operation can be spread out over a period of years, and if the tree is responsive you will be surprised at the amount of wood a big tree can lose during a five-year period and yet increase in size and cropping power.
Such pruning and thinning should be done when apple and pear trees are dormant but plums, cherries, and other stone fruits must be dealt with during the summer when there is a minimum of danger from silver leaf disease.
Dehorning is a technique applied to trees that tower up to a great height, making picking difficult and good spraying impossible. Pears are notorious offenders in this respect, and so are a few varieties of plum. Any variety which sends up strong, vertical branches can be improved by dehorning, cutting such branches back to a horizontally-growing side growth. A tree of 30 ft high will be far easier to handle if headed back to ten or fifteen feet according to the number and size of its branches. But as with thinning spread the work over two or three years.
As a result of this hard cutting-back many shoots will form near the points of amputation. Leave enough to form fruiting wood, but the many surplus shoots are best roughly sawn away or even pulled out by hand in summer. (Because careful pruning leaves behind many dormant buds which will grow out, this is a case where roughness pays.) Remember that plums and other stone fruits must be cut in the summer.
Copyright Gloucestershire Orchard Group
Thanks to the Gloucestershire Orchard Group and Gloucestershire County Council for kindly allowing Downsizer.net to publish this article. The Gloucestershire Orchard Group is an independent association founded in 2001 whose aim is to conserve, promote and celebrate traditional orchards in the county of Gloucestershire in the west of England. The group's website at http://www.orchard-group.uklinux.net/glos/index.html rovides extensive advice on the care and renovation of orchards, including identifying fruit, sourcing local varieties, dealing with pests and diseases, encouraging biodiversity, and details of events and orchards to visit.
For contact details of other UK orchard groups, see the National Orchard Forum website www.nat-orchard-forum.org.uk
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